It's better to put things under the wooden floor than not!

Under the wooden floor, a protective film is usually laid to prevent the moisture on the surface from affecting the floor, and some floor camphor wood chips and other insect repellent drugs can also be added.

As for some so-called feng shui experts who put coins on the floor, it's up to you. Most of them are the first comfort, which is of no practical significance. If you believe this, do it. If you don't understand the problem of Feng Shui, I suggest not to study it too much, because it is likely that someone will give some psychological hints and affect people's normal life.